Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 154
Filter
1.
Cell ; 153(6): 1327-39, 2013 Jun 06.
Article in English | MEDLINE | ID: mdl-23746844

ABSTRACT

The transcription factor HIF1A is a key mediator of the cellular response to hypoxia. Despite the importance of HIF1A in homeostasis and various pathologies, little is known about how it regulates RNA polymerase II (RNAPII). We report here that HIF1A employs a specific variant of the Mediator complex to stimulate RNAPII elongation. The Mediator-associated kinase CDK8, but not the paralog CDK19, is required for induction of many HIF1A target genes. HIF1A induces binding of CDK8-Mediator and the super elongation complex (SEC), containing AFF4 and CDK9, to alleviate RNAPII pausing. CDK8 is dispensable for HIF1A chromatin binding and histone acetylation, but it is essential for binding of SEC and RNAPII elongation. Global analysis of active RNAPII reveals that hypoxia-inducible genes are paused and active prior to their induction. Our results provide a mechanistic link between HIF1A and CDK8, two potent oncogenes, in the cellular response to hypoxia.


Subject(s)
Cell Hypoxia , Cyclin-Dependent Kinase 8/metabolism , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Mediator Complex/metabolism , Neoplasms/metabolism , RNA Polymerase II/metabolism , Transcription Elongation, Genetic , Acetylation , Cell Line, Tumor , Cyclin-Dependent Kinase 8/chemistry , Cyclin-Dependent Kinases/metabolism , HeLa Cells , Histones/metabolism , Humans
2.
J Virol ; 98(3): e0156323, 2024 Mar 19.
Article in English | MEDLINE | ID: mdl-38323811

ABSTRACT

Macrophages are important target cells for diverse viruses and thus represent a valuable system for studying virus biology. Isolation of primary human macrophages is done by culture of dissociated tissues or from differentiated blood monocytes, but these methods are both time consuming and result in low numbers of recovered macrophages. Here, we explore whether macrophages derived from human induced pluripotent stem cells (iPSCs)-which proliferate indefinitely and potentially provide unlimited starting material-could serve as a faithful model system for studying virus biology. Human iPSC-derived monocytes were differentiated into macrophages and then infected with HIV-1, dengue virus, or influenza virus as model human viruses. We show that iPSC-derived macrophages support the replication of these viruses with kinetics and phenotypes similar to human blood monocyte-derived macrophages. These iPSC-derived macrophages were virtually indistinguishable from human blood monocyte-derived macrophages based on surface marker expression (flow cytometry), transcriptomics (RNA sequencing), and chromatin accessibility profiling. iPSC lines were additionally generated from non-human primate (chimpanzee) fibroblasts. When challenged with dengue virus, human and chimpanzee iPSC-derived macrophages show differential susceptibility to infection, thus providing a valuable resource for studying the species-tropism of viruses. We also show that blood- and iPSC-derived macrophages both restrict influenza virus at a late stage of the virus lifecycle. Collectively, our results substantiate iPSC-derived macrophages as an alternative to blood monocyte-derived macrophages for the study of virus biology. IMPORTANCE: Macrophages have complex relationships with viruses: while macrophages aid in the removal of pathogenic viruses from the body, macrophages are also manipulated by some viruses to serve as vessels for viral replication, dissemination, and long-term persistence. Here, we show that iPSC-derived macrophages are an excellent model that can be exploited in virology.


Subject(s)
Dengue Virus , HIV-1 , Induced Pluripotent Stem Cells , Macrophages , Models, Biological , Orthomyxoviridae , Virology , Animals , Humans , Cell Differentiation/genetics , HIV-1/growth & development , HIV-1/physiology , Induced Pluripotent Stem Cells/cytology , Macrophages/cytology , Macrophages/metabolism , Macrophages/virology , Orthomyxoviridae/growth & development , Orthomyxoviridae/physiology , Pan troglodytes , Dengue Virus/growth & development , Dengue Virus/physiology , Fibroblasts/cytology , Monocytes/cytology , Virus Replication , Flow Cytometry , Gene Expression Profiling , Chromatin Assembly and Disassembly , Viral Tropism , Virology/methods , Biomarkers/analysis , Biomarkers/metabolism
3.
J Infect Dis ; 229(6): 1919-1925, 2024 Jun 14.
Article in English | MEDLINE | ID: mdl-38451247

ABSTRACT

Current serologic tests for HIV screening and confirmation of infection present challenges to the adoption of HIV vaccines. The detection of vaccine-induced HIV-1 antibodies in the absence of HIV-1 infection, referred to as vaccine-induced seropositivity/seroreactivity, confounds the interpretation of test results, causing misclassification of HIV-1 status with potential affiliated stigmatization. For HIV vaccines to be widely adopted with high community confidence and uptake, tests are needed that are agnostic to the vaccination status of tested individuals (ie, positive only for true HIV-1 infection). Successful development and deployment of such tests will require HIV vaccine developers to work in concert with diagnostic developers. Such tests will need to match today's high-performance standards (accuracy, cost-effectiveness, simplicity) for use in vaccinated and unvaccinated populations, especially in low- and middle-income countries with high HIV burden. Herein, we discuss the challenges and strategies for developing modified serologic HIV tests for concurrent deployment with HIV vaccines.


Subject(s)
AIDS Vaccines , HIV Infections , HIV-1 , Humans , HIV Infections/diagnosis , HIV Infections/prevention & control , AIDS Vaccines/immunology , HIV-1/immunology , HIV Antibodies/blood , HIV Antibodies/immunology , Serologic Tests/methods
4.
N Engl J Med ; 384(12): 1089-1100, 2021 03 25.
Article in English | MEDLINE | ID: mdl-33761206

ABSTRACT

BACKGROUND: A safe, effective vaccine is essential to eradicating human immunodeficiency virus (HIV) infection. A canarypox-protein HIV vaccine regimen (ALVAC-HIV plus AIDSVAX B/E) showed modest efficacy in reducing infection in Thailand. An analogous regimen using HIV-1 subtype C virus showed potent humoral and cellular responses in a phase 1-2a trial in South Africa. Efficacy data and additional safety data were needed for this regimen in a larger population in South Africa. METHODS: In this phase 2b-3 trial, we randomly assigned 5404 adults without HIV-1 infection to receive the vaccine (2704 participants) or placebo (2700 participants). The vaccine regimen consisted of injections of ALVAC-HIV at months 0 and 1, followed by four booster injections of ALVAC-HIV plus bivalent subtype C gp120-MF59 adjuvant at months 3, 6, 12, and 18. The primary efficacy outcome was the occurrence of HIV-1 infection from randomization to 24 months. RESULTS: In January 2020, prespecified criteria for nonefficacy were met at an interim analysis; further vaccinations were subsequently halted. The median age of the trial participants was 24 years; 70% of the participants were women. The incidence of adverse events was similar in the vaccine and placebo groups. During the 24-month follow-up, HIV-1 infection was diagnosed in 138 participants in the vaccine group and in 133 in the placebo group (hazard ratio, 1.02; 95% confidence interval, 0.81 to 1.30; P = 0.84). CONCLUSIONS: The ALVAC-gp120 regimen did not prevent HIV-1 infection among participants in South Africa despite previous evidence of immunogenicity. (HVTN 702 ClinicalTrials.gov number, NCT02968849.).


Subject(s)
AIDS Vaccines , Adjuvants, Immunologic , HIV Infections/prevention & control , HIV-1 , Immunogenicity, Vaccine , Polysorbates , Squalene , AIDS Vaccines/immunology , Adolescent , Adult , Canarypox virus , Double-Blind Method , Female , Genetic Vectors , HIV-1/genetics , Humans , Immunization, Secondary , Male , South Africa , Treatment Failure , Young Adult
5.
Hum Genomics ; 17(1): 83, 2023 09 05.
Article in English | MEDLINE | ID: mdl-37670378

ABSTRACT

BACKGROUND: RUNX1 is a transcription factor and a master regulator for the specification of the hematopoietic lineage during embryogenesis and postnatal megakaryopoiesis. Mutations and rearrangements on RUNX1 are key drivers of hematological malignancies. In humans, this gene is localized to the 'Down syndrome critical region' of chromosome 21, triplication of which is necessary and sufficient for most phenotypes that characterize Trisomy 21. MAIN BODY: Individuals with Down syndrome show a higher predisposition to leukemias. Hence, RUNX1 overexpression was initially proposed as a critical player on Down syndrome-associated leukemogenesis. Less is known about the functions of RUNX1 in other tissues and organs, although growing reports show important implications in development or homeostasis of neural tissues, muscle, heart, bone, ovary, or the endothelium, among others. Even less is understood about the consequences on these tissues of RUNX1 gene dosage alterations in the context of Down syndrome. In this review, we summarize the current knowledge on RUNX1 activities outside blood/leukemia, while suggesting for the first time their potential relation to specific Trisomy 21 co-occurring conditions. CONCLUSION: Our concise review on the emerging RUNX1 roles in different tissues outside the hematopoietic context provides a number of well-funded hypotheses that will open new research avenues toward a better understanding of RUNX1-mediated transcription in health and disease, contributing to novel potential diagnostic and therapeutic strategies for Down syndrome-associated conditions.


Subject(s)
Down Syndrome , Female , Humans , Core Binding Factor Alpha 2 Subunit , Hematopoiesis , Chromosomes, Human, Pair 21 , Carcinogenesis
6.
BMC Health Serv Res ; 24(1): 253, 2024 Feb 28.
Article in English | MEDLINE | ID: mdl-38414045

ABSTRACT

BACKGROUND: Germline cancer genetic testing has become a standard evidence-based practice, with established risk reduction and screening guidelines for genetic carriers. Access to genetic services is limited in many places, which leaves many genetic carriers unidentified and at risk for late diagnosis of cancers and poor outcomes. This poses a problem for childhood cancer survivors, as this is a population with an increased risk for subsequent malignant neoplasms (SMN) due to cancer therapy or inherited cancer predisposition. The ENGaging and Activating cancer survivors in Genetic services (ENGAGE) study evaluates the effectiveness of an in-home, collaborative PCP model of remote telegenetic services to increase uptake of cancer genetic testing in childhood cancer survivors compared to usual care options for genetic testing. METHODS: The ENGAGE study is a 3-arm randomized hybrid type 1 effectiveness and implementation study within the Childhood Cancer Survivor Study population which tests a clinical intervention while gathering information on its delivery during the effectiveness trial and its potential for future implementation among 360 participants. Participants are randomized into three arms. Those randomized to Arm A receive genetic services via videoconferencing, those in Arm B receive these services by phone, and those randomized to Arm C will receive usual care services. DISCUSSION: With many barriers to accessing genetic services, innovative delivery models are needed to address this gap and increase uptake of genetic services. The ENGAGE study evaluates the effectiveness of an adapted model of remote delivery of genetic services to increase the uptake of recommended genetic testing in childhood cancer survivors. This study assesses the uptake in remote genetic services and identify barriers to uptake to inform future recommendations and a theoretically-informed process evaluation which can inform modifications to enhance dissemination beyond this study population and to realize the benefits of precision medicine. TRIAL REGISTRATION: This protocol was registered at clinicaltrials.gov (NCT04455698) on July 2, 2020.


Subject(s)
Cancer Survivors , Neoplasms , Humans , Child , Neoplasms/genetics , Genetic Testing
7.
BMC Biol ; 21(1): 228, 2023 11 10.
Article in English | MEDLINE | ID: mdl-37946204

ABSTRACT

BACKGROUND: The increase in DNA copy number in Down syndrome (DS; caused by trisomy 21) has led to the DNA dosage hypothesis, which posits that the level of gene expression is proportional to the gene's DNA copy number. Yet many reports have suggested that a proportion of chromosome 21 genes are dosage compensated back towards typical expression levels (1.0×). In contrast, other reports suggest that dosage compensation is not a common mechanism of gene regulation in trisomy 21, providing support to the DNA dosage hypothesis. RESULTS: In our work, we use both simulated and real data to dissect the elements of differential expression analysis that can lead to the appearance of dosage compensation, even when compensation is demonstrably absent. Using lymphoblastoid cell lines derived from a family with an individual with Down syndrome, we demonstrate that dosage compensation is nearly absent at both nascent transcription (GRO-seq) and steady-state RNA (RNA-seq) levels. Furthermore, we link the limited apparent dosage compensation to expected allelic variation in transcription levels. CONCLUSIONS: Transcription dosage compensation does not occur in Down syndrome. Simulated data containing no dosage compensation can appear to have dosage compensation when analyzed via standard methods. Moreover, some chromosome 21 genes that appear to be dosage compensated are consistent with allele specific expression.


Subject(s)
Down Syndrome , Humans , Down Syndrome/genetics , X Chromosome , Dosage Compensation, Genetic , Gene Expression Regulation , DNA
8.
BMC Med Res Methodol ; 23(1): 147, 2023 06 24.
Article in English | MEDLINE | ID: mdl-37355583

ABSTRACT

BACKGROUND: To produce quality data that informs valid clinical trial results and withstands regulatory inspection, trial sites should adhere to many complex and dynamic requirements. Understanding non-conformance to requirements informs the emerging field of improvement science. We describe protocol deviations in South Africa's largest HIV vaccine efficacy trial. METHODS: We analysed data from the HVTN 702 trial using mixed methods. We obtained descriptive statistics, from protocol deviation case report forms collected from 2016-2022, of deviation by participant, trial site, and time to site awareness. We thematically analysed text narratives of deviation descriptions, corrective and preventive actions, generating categories, codes and themes which emerged from the data. RESULTS: For 5407 enrollments, 4074 protocol deviations were reported (75 [95% CI: 73.0-77.6] deviations per 100 enrolments). There was a median of 1 protocol deviation per participant (IQR 1-2). Median time from deviation to site awareness was 31 days (IQR 0-146). The most common category of deviation type was omitted data and/or procedures (69%), and 54% of these omissions were stated to have arisen because of the national lockdown at the beginning of the COVID-19 pandemic. The ratio of protocol deviations to cumulative enrolments was highest in the year 2020 (0.34). Major themes of deviations were: COVID-19 and climate disasters giving rise to deviation trends, subroutines introducing an opportunity for deviation, and document fragmentation (such as requirements dispersed across multiple guidance documents) as an obstacle. Preventive action categories were: no preventive measures; discipline, training and/or awareness; quality review, checking and verifying and changing the process and/or implementation tools. Major themes of preventive actions were that systems-based actions are unusual, with people-based actions dominating, and that root cause analysis was rarely mentioned. CONCLUSIONS: In the age of infectious and climate disaster risks, trials may benefit from simple study designs and trial-related documents. To optimise protocol adherence, sponsors and sites should consider ongoing training, and routinely review deviation reports with a view to adjusting processes. These data quality lessons may inform future trial design, training and implementation. TRIAL REGISTRATION: HVTN 702 was registered with the South African National Clinical Trials Register (DOH-27-0916-5327) and ClinicalTrials.gov ( NCT02968849 ).


Subject(s)
COVID-19 , HIV Infections , Natural Disasters , Humans , Communicable Disease Control , Data Accuracy , HIV Infections/prevention & control , Pandemics/prevention & control , South Africa , Vaccine Efficacy , Clinical Trials as Topic
9.
AIDS Behav ; 27(4): 1314-1320, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36287343

ABSTRACT

Many early phase HIV prevention studies define HIV risk-related eligibility criteria. We conducted a retrospective review of HIV Vaccine Trials Network (HVTN) Phase 1 and 2 HIV vaccine clinical trials completed in South Africa from 2003 to 2020, evaluating HIV incidence by protocol-defined risk criteria. Comparisons between groups controlled for age, gender and year of trial initiation. Across 12 trials, 1 did not specify risk criteria, and 11 specified various low risk criteria thematically categorized under sexual behaviors, clinical characteristics, and/or drug use behavior. Of the 11 trials, 6 used low sexual risk eligibility criteria standardized by the HVTN in 2009. Of the 1249 participants, median age 23.0 years, 66% were enrolled with the HVTN 2009 standardized low risk criteria, 15% using other sets of low risk criteria, and 19% using no risk criteria. Compared with the standardized low risk criteria group [2.3], HIV incidence per 100 person-years was significantly higher in the non-standardized low risk criteria group [5.0] and in the no risk criteria group [4.8]. In South Africa, cohorts with low HIV incidence can be identified primarily through sexual behavior and clinical characteristics.


Subject(s)
AIDS Vaccines , HIV Infections , HIV-1 , Adult , Humans , Young Adult , HIV Infections/diagnosis , HIV Infections/epidemiology , HIV Infections/prevention & control , Incidence , South Africa/epidemiology
10.
AIDS Behav ; 27(9): 3027-3037, 2023 Sep.
Article in English | MEDLINE | ID: mdl-36929319

ABSTRACT

In South Africa, HIV acquisition risk has been studied less in people assigned male at birth. We studied the associations between risk behaviors, clinical features and HIV incidence amongst males in two South African HIV preventive vaccine efficacy trials. We used Cox proportional hazards models to test for associations between demographics, sexual behaviors, clinical variables and HIV acquisition among males followed in the HVTN 503 (n = 219) and HVTN 702 (n = 1611) trials. Most males reported no male sexual partners (99.09% in HVTN 503) or identified as heterosexual (88.08% in HVTN 702). Annual HIV incidence was 1.39% in HVTN 503 (95% CI 0.76-2.32%) and 1.33% in HVTN 702 (95% CI 0.80-2.07%). Increased HIV acquisition was significantly associated with anal sex (HR 6.32, 95% CI 3.44-11.62), transactional sex (HR 3.42, 95% CI 1.80-6.50), and non-heterosexual identity (HR 16.23, 95%CI 8.13-32.41) in univariate analyses and non-heterosexual identity (HR 14.99, 95% CI 4.99-45.04; p < 0.01) in multivariate analysis. It is appropriate that prevention efforts in South Africa, although focused on the severe epidemic in young women, also encompass key male populations, including men who have sex with men, but also men who engage in anal or transactional sex.


Subject(s)
AIDS Vaccines , HIV Infections , Sexual and Gender Minorities , Humans , Male , HIV Infections/epidemiology , HIV Infections/prevention & control , Homosexuality, Male , Risk Factors , Sexual Behavior , South Africa/epidemiology , Vaccine Efficacy , Clinical Trials as Topic
11.
J Infect Dis ; 226(2): 246-257, 2022 08 24.
Article in English | MEDLINE | ID: mdl-35758878

ABSTRACT

BACKGROUND: The ALVAC/gp120 + MF59 vaccines in the HIV Vaccine Trials Network (HVTN) 702 efficacy trial did not prevent human immunodeficiency virus-1 (HIV-1) acquisition. Vaccine-matched immunological endpoints that were correlates of HIV-1 acquisition risk in RV144 were measured in HVTN 702 and evaluated as correlates of HIV-1 acquisition. METHODS: Among 1893 HVTN 702 female vaccinees, 60 HIV-1-seropositive cases and 60 matched seronegative noncases were sampled. HIV-specific CD4+ T-cell and binding antibody responses were measured 2 weeks after fourth and fifth immunizations. Cox proportional hazards models assessed prespecified responses as predictors of HIV-1 acquisition. RESULTS: The HVTN 702 Env-specific CD4+ T-cell response rate was significantly higher than in RV144 (63% vs 40%, P = .03) with significantly lower IgG binding antibody response rate and magnitude to 1086.C V1V2 (67% vs 100%, P < .001; Pmag < .001). Although no significant univariate associations were observed between any T-cell or binding antibody response and HIV-1 acquisition, significant interactions were observed (multiplicity-adjusted P ≤.03). Among vaccinees with high IgG A244 V1V2 binding antibody responses, vaccine-matched CD4+ T-cell endpoints associated with decreased HIV-1 acquisition (estimated hazard ratios = 0.40-0.49 per 1-SD increase in CD4+ T-cell endpoint). CONCLUSIONS: HVTN 702 and RV144 had distinct immunogenicity profiles. However, both identified significant correlations (univariate or interaction) for IgG V1V2 and polyfunctional CD4+ T cells with HIV-1 acquisition. Clinical Trials Registration . NCT02968849.


Subject(s)
AIDS Vaccines , HIV Infections , HIV Seropositivity , HIV-1 , Female , HIV Antibodies , HIV Envelope Protein gp120 , HIV Infections/prevention & control , Humans , Immunoglobulin G , Male , South Africa
12.
BMC Genomics ; 23(1): 187, 2022 Mar 07.
Article in English | MEDLINE | ID: mdl-35255806

ABSTRACT

BACKGROUND: A variety of protocols exist for producing whole genome run-on transcription datasets. However, little is known about how differences between these protocols affect the signal within the resulting libraries. RESULTS: Using run-on transcription datasets generated from the same biological system, we show that a variety of GRO- and PRO-seq preparation methods leave identifiable signatures within each library. Specifically we show that the library preparation method results in differences in quality control metrics, as well as differences in the signal distribution at the 5 ' end of transcribed regions. These shifts lead to disparities in eRNA identification, but do not impact analyses aimed at inferring the key regulators involved in changes to transcription. CONCLUSIONS: Run-on sequencing protocol variations result in technical signatures that can be used to identify both the enrichment and library preparation method of a particular data set. These technical signatures are batch effects that limit detailed comparisons of pausing ratios and eRNAs identified across protocols. However, these batch effects have only limited impact on our ability to infer which regulators underlie the observed transcriptional changes.


Subject(s)
Genomic Library , High-Throughput Nucleotide Sequencing , Databases, Genetic , High-Throughput Nucleotide Sequencing/methods , Quality Control , Transcription, Genetic
13.
Genome Res ; 29(11): 1753-1765, 2019 11.
Article in English | MEDLINE | ID: mdl-31519741

ABSTRACT

The glucocorticoid receptor (NR3C1, also known as GR) binds to specific DNA sequences and directly induces transcription of anti-inflammatory genes that contribute to cytokine repression, frequently in cooperation with NF-kB. Whether inflammatory repression also occurs through local interactions between GR and inflammatory gene regulatory elements has been controversial. Here, using global run-on sequencing (GRO-seq) in human airway epithelial cells, we show that glucocorticoid signaling represses transcription within 10 min. Many repressed regulatory regions reside within "hyper-ChIPable" genomic regions that are subject to dynamic, yet nonspecific, interactions with some antibodies. When this artifact was accounted for, we determined that transcriptional repression does not require local GR occupancy. Instead, widespread transcriptional induction through canonical GR binding sites is associated with reciprocal repression of distal TNF-regulated enhancers through a chromatin-dependent process, as evidenced by chromatin accessibility and motif displacement analysis. Simultaneously, transcriptional induction of key anti-inflammatory effectors is decoupled from primary repression through cooperation between GR and NF-kB at a subset of regulatory regions. Thus, glucocorticoids exert bimodal restraints on inflammation characterized by rapid primary transcriptional repression without local GR occupancy and secondary anti-inflammatory effects resulting from transcriptional cooperation between GR and NF-kB.


Subject(s)
Dexamethasone/pharmacology , Inflammation/metabolism , RNA, Messenger/genetics , Receptors, Glucocorticoid/metabolism , Tumor Necrosis Factor-alpha/pharmacology , Chromatin/metabolism , Dexamethasone/metabolism , Enhancer Elements, Genetic , HEK293 Cells , Humans , NF-kappa B/metabolism , Signal Transduction
14.
Infect Immun ; 89(11): e0027321, 2021 10 15.
Article in English | MEDLINE | ID: mdl-34370511

ABSTRACT

Nutritional immunity involves cellular and physiological responses to invading pathogens, such as limiting iron, increasing exposure to bactericidal copper, and altering zinc to restrict the growth of pathogens. Here, we examine infection of bone marrow-derived macrophages from 129S6/SvEvTac mice by Salmonella enterica serovar Typhimurium. The 129S6/SvEvTac mice possess a functional Slc11a1 (Nramp-1), a phagosomal transporter of divalent cations that plays an important role in modulating metal availability to the pathogen. We carried out global RNA sequencing upon treatment with live or heat-killed Salmonella at 2 h and 18 h postinfection and observed widespread changes in metal transport, metal-dependent genes, and metal homeostasis genes, suggesting significant remodeling of iron, copper, and zinc availability by host cells. Changes in host cell gene expression suggest infection increases cytosolic zinc while simultaneously limiting zinc within the phagosome. Using a genetically encoded sensor, we demonstrate that cytosolic labile zinc increases 45-fold at 12 h postinfection. Further, manipulation of zinc in the medium alters bacterial clearance and replication, with zinc depletion inhibiting both processes. Comparing the transcriptomic changes to published data on infection of C57BL/6 macrophages revealed notable differences in metal regulation and the global immune response. Our results reveal that 129S6 macrophages represent a distinct model system compared to C57BL/6 macrophages. Further, our results indicate that manipulation of zinc at the host-pathogen interface is more nuanced than that of iron or copper. The 129S6 macrophages leverage intricate means of manipulating zinc availability and distribution to limit the pathogen's access to zinc, while simultaneously ensuring sufficient zinc to support the immune response.


Subject(s)
Macrophages/immunology , Metals/metabolism , Salmonella Infections, Animal/immunology , Animals , Complement System Proteins/immunology , Female , Gene Expression , Host-Pathogen Interactions , Mice , Mice, Inbred C57BL , Salmonella typhimurium , Zinc/metabolism
15.
Genome Res ; 2018 Feb 15.
Article in English | MEDLINE | ID: mdl-29449408

ABSTRACT

Transcription factors (TFs) exert their regulatory influence through the binding of enhancers, resulting in coordination of gene expression programs. Active enhancers are often characterized by the presence of short, unstable transcripts termed enhancer RNAs (eRNAs). While their function remains unclear, we demonstrate that eRNAs are a powerful readout of TF activity. We infer sites of eRNA origination across hundreds of publicly available nascent transcription data sets and show that eRNAs initiate from sites of TF binding. By quantifying the colocalization of TF binding motif instances and eRNA origins, we derive a simple statistic capable of inferring TF activity. In doing so, we uncover dozens of previously unexplored links between diverse stimuli and the TFs they affect.

16.
BMC Infect Dis ; 21(1): 802, 2021 Aug 11.
Article in English | MEDLINE | ID: mdl-34380464

ABSTRACT

BACKGROUND: Pregnancies occur during HIV-1 vaccine clinical trials, despite requirements for women of reproductive potential to use effective contraception. Deployment of an effective HIV-1 vaccine regimen will likely target adolescents and young adults and therefore safety for pregnant and breastfeeding women will need to be addressed. METHODS: We performed a retrospective, cross-protocol analysis to identify and compare pregnancy outcomes reported in 53 Phase 1 and Phase 2a HIV-1 vaccine clinical trials conducted by the HIV Vaccine Trials Network (HVTN). RESULTS: Two thousand six hundred seventy-three women of reproductive potential were identified and 193 pregnancies were reported. 39 of 53 (74%) studies had at least one pregnancy reported with an overall pregnancy rate of 3.15 per 100 woman-years (w-yr). While active contraception use was required during study participation, 13 of the 53 studies also contained a long-term follow up period during which pregnancy was no longer discouraged. The pregnancy rate during main study participation was 3.09 per 100 w-yr, while pregnancies occurred at a slightly greater rate in the long-term follow up period (3.22 per 100 w-yr). Adverse pregnancy outcomes were reported at similar rates between vaccinees and placebo recipients when vaccine vectors, adjuvant used, or geographic region were examined. CONCLUSION: Although there is considerable heterogeneity amongst the different vaccine trials, there appears to be no obvious indication of increased risk of adverse pregnancy or birth outcomes in these early phase HIV-1 vaccine studies. More complete data on pregnancy outcomes should be collected in early phase HIV-1 vaccine clinical trials to better inform subsequent efficacy trials.


Subject(s)
AIDS Vaccines , HIV Infections , HIV-1 , AIDS Vaccines/therapeutic use , Adolescent , Drug Therapy, Combination , Female , HIV Infections/drug therapy , HIV Infections/prevention & control , Humans , Pregnancy , Retrospective Studies , Young Adult
17.
PLoS Med ; 17(2): e1003038, 2020 02.
Article in English | MEDLINE | ID: mdl-32092060

ABSTRACT

BACKGROUND: HVTN 100 evaluated the safety and immunogenicity of an HIV subtype C pox-protein vaccine regimen, investigating a 12-month booster to extend vaccine-induced immune responses. METHODS AND FINDINGS: A phase 1-2 randomized double-blind placebo-controlled trial enrolled 252 participants (210 vaccine/42 placebo; median age 23 years; 43% female) between 9 February 2015 and 26 May 2015. Vaccine recipients received ALVAC-HIV (vCP2438) alone at months 0 and 1 and with bivalent subtype C gp120/MF59 at months 3, 6, and 12. Antibody (IgG, IgG3 binding, and neutralizing) and CD4+ T-cell (expressing interferon-gamma, interleukin-2, and CD40 ligand) responses were evaluated at month 6.5 for all participants and at months 12, 12.5, and 18 for a randomly selected subset. The primary analysis compared IgG binding antibody (bAb) responses and CD4+ T-cell responses to 3 vaccine-matched antigens at peak (month 6.5 versus 12.5) and durability (month 12 versus 18) timepoints; IgG responses to CaseA2_gp70_V1V2.B, a primary correlate of risk in RV144, were also compared at these same timepoints. Secondary and exploratory analyses compared IgG3 bAb responses, IgG bAb breadth scores, neutralizing antibody (nAb) responses, antibody-dependent cellular phagocytosis, CD4+ polyfunctionality responses, and CD4+ memory sub-population responses at the same timepoints. Vaccines were generally safe and well tolerated. During the study, there were 2 deaths (both in the vaccine group and both unrelated to study products). Ten participants became HIV-infected during the trial, 7% (3/42) of placebo recipients and 3% (7/210) of vaccine recipients. All 8 serious adverse events were unrelated to study products. Less waning of immune responses was seen after the fifth vaccination than after the fourth, with higher antibody and cellular response rates at month 18 than at month 12: IgG bAb response rates to 1086.C V1V2, 21.0% versus 9.7% (difference = 11.3%, 95% CI = 0.6%-22.0%, P = 0.039), and ZM96.C V1V2, 21.0% versus 6.5% (difference = 14.5%, 95% CI = 4.1%-24.9%, P = 0.004). IgG bAb response rates to all 4 primary V1V2 antigens were higher 2 weeks after the fifth vaccination than 2 weeks after the fourth vaccination: 87.7% versus 75.4% (difference = 12.3%, 95% CI = 1.7%-22.9%, P = 0.022) for 1086.C V1V2, 86.0% versus 63.2% (difference = 22.8%, 95% CI = 9.1%-36.5%, P = 0.001) for TV1c8.2.C V1V2, 67.7% versus 44.6% (difference = 23.1%, 95% CI = 10.4%-35.7%, P < 0.001) for ZM96.C V1V2, and 81.5% versus 60.0% (difference = 21.5%, 95% CI = 7.6%-35.5%, P = 0.002) for CaseA2_gp70_V1V2.B. IgG bAb response rates to the 3 primary vaccine-matched gp120 antigens were all above 90% at both peak timepoints, with no significant differences seen, except a higher response rate to ZM96.C gp120 at month 18 versus month 12: 64.5% versus 1.6% (difference = 62.9%, 95% CI = 49.3%-76.5%, P < 0.001). CD4+ T-cell response rates were higher at month 18 than month 12 for all 3 primary vaccine-matched antigens: 47.3% versus 29.1% (difference = 18.2%, 95% CI = 2.9%-33.4%, P = 0.021) for 1086.C, 61.8% versus 38.2% (difference = 23.6%, 95% CI = 9.5%-37.8%, P = 0.001) for TV1.C, and 63.6% versus 41.8% (difference = 21.8%, 95% CI = 5.1%-38.5%, P = 0.007) for ZM96.C, with no significant differences seen at the peak timepoints. Limitations were that higher doses of gp120 were not evaluated, this study was not designed to investigate HIV prevention efficacy, and the clinical significance of the observed immunological effects is uncertain. CONCLUSIONS: In this study, a 12-month booster of subtype C pox-protein vaccines restored immune responses, and slowed response decay compared to the 6-month vaccination. TRIAL REGISTRATION: ClinicalTrials.gov NCT02404311. South African National Clinical Trials Registry (SANCTR number: DOH--27-0215-4796).


Subject(s)
AIDS Vaccines/therapeutic use , Antibodies, Neutralizing/immunology , CD4-Positive T-Lymphocytes/immunology , HIV Infections/prevention & control , Human Immunodeficiency Virus Proteins/immunology , Immunization, Secondary , Immunoglobulin G/immunology , AIDS Vaccines/immunology , Adult , Arthralgia/chemically induced , Double-Blind Method , Female , Headache/chemically induced , Humans , Immunogenicity, Vaccine , Injection Site Reaction , Injections, Intramuscular , Male , South Africa , Young Adult
18.
PLoS Med ; 17(5): e1003117, 2020 05.
Article in English | MEDLINE | ID: mdl-32442195

ABSTRACT

BACKGROUND: DNA plasmids promise a pragmatic alternative to viral vectors for prime-boost HIV-1 vaccines. We evaluated DNA plasmid versus canarypox virus (ALVAC) primes in 2 randomized, double-blind, placebo-controlled trials in southern Africa with harmonized trial designs. HIV Vaccine Trials Network (HVTN) 111 tested DNA plasmid prime by needle or needleless injection device (Biojector) and DNA plasmid plus gp120 protein plus MF59 adjuvant boost. HVTN 100 tested ALVAC prime and ALVAC plus gp120 protein plus MF59 adjuvant boost (same protein/adjuvant as HVTN 111) by needle. METHODS AND FINDINGS: The primary endpoints for this analysis were binding antibody (bAb) responses to HIV antigens (gp120 from strains ZM96, 1086, and TV1; variable 1 and 2 [V1V2] regions of gp120 from strains TV1, 1086, and B.CaseA, as 1086 V1V2 and B.CaseA were correlates of risk in the RV144 efficacy trial), neutralizing antibody (nAb) responses to pseudoviruses TV1c8.2 and MW925.26, and cellular responses to vaccine-matched antigens (envelope [Env] from strains ZM96, 1086, and TV1; and Gag from strains LAI and ZM96) at month 6.5, two weeks after the fourth vaccination. Per-protocol cohorts included vaccine recipients from HVTN 100 (n = 186, 60% male, median age 23 years) enrolled between February 9, 2015, and May 26, 2015 and from HVTN 111 (n = 56, 48% male, median age 24 years) enrolled between June 21, 2016, and July 13, 2017. IgG bAb response rates were 100% to 3 Env gp120 antigens in both trials. Response rates to V1V2 were lower and similar in both trials except to vaccine-matched 1086 V1V2, with rates significantly higher for the DNA-primed regimen than the ALVAC-primed regimen: 96.6% versus 72.7% (difference = 23.9%, 95% CI 15.6%-32.2%, p < 0.001). Among positive responders, bAb net mean fluorescence intensity (MFI) was significantly higher with the DNA-primed regimen than ALVAC-primed for 1086 V1V2 (geometric mean [GM] 2,833.3 versus 1,200.9; ratio = 2.36, 95% CI 1.42-3.92, p < 0.001) and B.CaseA V1V2 (GM 2314.0 versus 744.6, ratio = 3.11, 95% CI 1.51-6.38, p = 0.002). nAb response rates were >98% in both trials, with significantly higher 50% inhibitory dilution (ID50) among DNA-primed positive responders (n = 53) versus ALVAC-primed (n = 182) to tier 1A MW965.26 (GM 577.7 versus 265.7, ratio = 2.17, 95% CI 1.67-2.83, p < 0.001) and to TV1c8.2 (GM 187.3 versus 100.4, ratio = 1.87, 95% CI 1.48-2.35, p < 0.001). CD4+ T-cell response rates were significantly higher with DNA plasmid prime via Biojector than ALVAC prime (91.4% versus 52.8%, difference = 38.6%, 95% CI 20.5%-56.6%, p < 0.001 for ZM96.C; 88.0% versus 43.1%, difference = 44.9%, 95% CI 26.7%-63.1%, p < 0.001 for 1086.C; 55.5% versus 2.2%, difference = 53.3%, 95% CI 23.9%-82.7%, p < 0.001 for Gag LAI/ZM96). The study's main limitations include the nonrandomized comparison of vaccines from 2 different trials, the lack of data on immune responses to other non-vaccine-matched antigens, and the uncertain clinical significance of the observed immunological effects. CONCLUSIONS: In this study, we found that further investigation of DNA/protein regimens is warranted given enhanced immunogenicity to the V1V2 correlates of decreased HIV-1 acquisition risk identified in RV144, the only HIV vaccine trial to date to show any efficacy.


Subject(s)
AIDS Vaccines/immunology , Antibodies, Neutralizing/immunology , HIV Antibodies/immunology , Adult , Antibody Formation/immunology , DNA/genetics , Double-Blind Method , Female , Genetic Vectors , HIV Antigens/immunology , HIV Infections/prevention & control , HIV-1/genetics , HIV-1/immunology , Humans , Male , Plasmids/genetics , Vaccination/methods , Young Adult
20.
J Insect Sci ; 19(2)2019 Mar 01.
Article in English | MEDLINE | ID: mdl-30843583

ABSTRACT

The complex biologies of pestiferous mosquito species complicate the development of a single, across the board effective control measure. The use of traditional biological control through predators, parasitoids, and microbes, though part of a multimodal, integrated pest management approach, is scant in current standard mosquito control operations. At this time, traditional, whole organism mosquito biocontrol agents are not commercially available, and if their integration into a release program is desired, they must be developed in-house. The aim of our program was to incorporate releasing natural enemies to disrupt and suppress the target pest mosquito's population by matching the agent with the target's biology, before or concurrent to pesticide use. A current focus is suppressing peridomestic, container breeders of high medical significance, such as Aedes aegypti (Linnaeus), (Diptera, Culicidae) and Aedes albopictus (Skuse) (Diptera, Culicidae), through larval reduction with augmentative releases of laboratory-reared, native mosquito assassins Toxorhynchites rutilus septentrionalis (Dyar & Knab). When raised in communal settings, Tx. rutilus' aggressive feeding behavior and cannibalistic tendencies require an extreme loss tolerance in adult production rates. In addition, offering prey mosquitoes exclusively as Tx. rutilus' juvenile food extends larval development by multiple days. While this may be desirous in the wild, it proves inefficient during production. Here, we provide an individual rearing method as well as an alternative diet protocol, which maximizes the adult yield while achieving quick development.


Subject(s)
Culicidae/growth & development , Entomology/methods , Animals , Female , Male , Pest Control, Biological
SELECTION OF CITATIONS
SEARCH DETAIL